Disable broken oslo jobs

The gate job for stevedore docs was turned on recently,
but the requirements for building those docs are not allowed
and we are in feature-freeze so we can't add them, yet.
Make the job non-voting so we aren't blocked setting up
library test jobs.

The requirements job for cliff is failing because the master
branch has duplicate requirements and the parser is complaining
before it verifies that an update fixes the problem.

Change-Id: I40b2cf4030df66c851d7d11da4f81f645d110e76
Merge "Disable broken oslo jobs"